<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script>
        var obj1 = {};
        var obj2 = new Object()
        // console.log(Object.prototype)
        // console.log(Array.prototype)
        // console.log(Date.prototype)
        var o3 = Object.create(Object.prototype);
        // console.log(o3)

        let book = {
            author: 'author',
            surname: 'surname',
            'main title': 'main title'
        }
        let author = book.author;
        book.edition = 6;
        book['main title'] = 'mainTitle'; // 表达式
        console.log(book)
        console.log('author'+ ':'+ author)
    </script>
</body>
</html>
